C3 Corvette Ignition - Distribution Of Power

MSD Ignition Upgrades Set Our C3's Spark System Ablaze

MSD Ignition's Digital E-Curve distributor is a direct replacement for your OEM points- or HEI-type distributor. It requires only three simple wiring connections and an hour or two of your time.

As with most things automotive, the ignition system has a fairly simple task. The job of the distributor and coil is to deliver spark to the proper cylinder at just the right time to create combustion. While this seems basic enough, it gets complicated quickly when it comes to optimizing the system for different conditions. Things like adjusting centrifugal and vacuum advance can easily overwhelm the novice tuner. This is where the innovation and flexibility of the MSD Ignition E-Curve Pro-Billet Distributor can save the day.

The E-Curve will drop right into your small- or big-block engine and requires you to connect only three wires. While that's cool, what really sets the E-Curve apart is that it's a stand-alone unit with no external boxes or controllers to operate. Its built-in high-output ignition module produces a powerful spark for improved combustion.

The other thing that makes the E-Curve unique is that it allows you to set a timing curve by simply twisting a rotary dial. The E-Curve's digital module lets you select from 20 different centrifugal curves and five vacuum curves, giving you 100 combinations from which to choose. The dials are easily accessed by removing the distributor cap. You can also set an rpm limit to protect your engine from damage caused by a missed shift or driveline failure. The rev limiter is adjustable from 5,000-10,000 rpm.

The digitally controlled ignition module is what makes these adjustments possible. The E-Curve uses MSD's proprietary magnetic pickup for an accurate trigger signal throughout the engine's entire operating range. Like all billet MSD distributors, the E-Curve is machined from a solid billet of 6000-series aluminum for unsurpassed accuracy and reliability. The tool-steel shaft is equipped with a heavy-duty gear and spins effortlessly on sealed ball-bearing assemblies. And finally, the E-Curve Distributor is topped with MSD's Rynite molded cap and rotor. It's even supplied with a matching three-pin Weathertight harness that makes wiring a snap.

An MSD Blaster Coil makes a natural companion piece to the E-Curve or any high-end distributor. MSD says the Blaster Coil line is designed for a maximum spark output of 45,000 volts! This is achieved through the use of special 100:1 windings that are held secure and kept cool in an oil-filled metal canister. The tower assembly is molded of durable alkyd material with high dielectric characteristics, while widely spaced brass primary terminals prevent the possibility of spark.

There are several versions of the Blaster Coil available, all of which have identical internal specifications. The only real difference is the housing configuration. We chose the traditional Blaster 2, which is available in MSD red or ultra-chic chrome.

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Make a drawing that illustrates the orientation of the rotor once the cap is off. Another option is to make a mark on the intake manifold with which the rotor will line up. Either way, this will make your life much easier when you install the MSD unit.

Topping off our MSD install is a set of the company's 8.5mm Super Conductor plug wires. These may be the finest wires available, offering incredibly low resistance while fending off all electronic interference. The secret is the low resistance: According to MSD, a 12-inch length of Super Conductor Wire has only 40-50 ohms of resistance, the lowest of any helically wound wire. To do this, MSD uses a copper alloy conductor, which offers excellent voltage-carrying capabilities. The conductor is wound so tight around its center core that it uses over 40 feet of conductor for a single foot of plug wire. Why should you care? Because the low resistance of these wires results in maximum spark energy reaching the plug.

Lastly, all MSD spark plug wires feature "Dual Crimp" terminals. As the name implies, each terminal features two crimps: one for the sleeve of the wire and another to grasp the conductor. This provides a more secure crimp and less chance of spark arcing to the engine block or exhaust through the boot. MSD is so confident in its Dual Crimp terminals that it warrants each factory-crimped plug wire against "pulling off" for five years. The 8.5mm Super Conductor Plug Wire is available in Universal Kits and Bulk Lengths in either red or black.

For this project, we chose a lightly modified '72 LS5 coupe. The owner noted a high-rpm miss that was traced to a low-quality electronic ignition conversion kit that was previously installed. Follow along as we take you through the steps required to swap out the parts. Note that exact timing numbers and curves have been intentionally left out, as every car is different. If you're unsure what timing will be best for your car, consult your factory service manual or give MSD's customer-service line a ring. They're truly experts at this stuff.

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MSD Ignition's Digital E-Curve distributor is a direct replacement for your OEM points- or HEI-type distributor. It requires only three simple wiring connections and an hour or two of your time.

Before starting disassembly, it's a good idea to verify the ignition timing currently being used. Make note of this, as you will want to duplicate it (at least as a starting point) once the MSD unit is installed.

The chrome "tissue dispenser" needs to be removed to gain access to the distributor.

Remove the plug wires from the spark plugs, then pull the distributor cap.

Make a drawing that illustrates the orientation of the rotor once the cap is off. Another option is to make a mark on the intake manifold with which the rotor will line up. Either way, this will make your life much easier when you install the MSD unit.

Disconnect the distributor's three-wire connector.

Next, remove the vacuum line from the vacuum-advance canister on the distributor. You should also remove the bolt and distributor hold-down bracket.

Since '72s have mechanically driven tachometers, you must also remove the drive from the distributor.

With all of this accomplished, you can remove the distributor. Notice the cast-aluminum construction of the housing on this unit.

MSD's distributor housing is CNC-machined from an aluminum billet and uses high-quality sealed ball bearings. The two rotary dials shown here control the centrifugal and vacuum advance timing curves. A third dial (not shown) controls the rev limiter.

This port for the vacuum-advance signal is located on the bottom, where it won't interfere with wiring.

MSD engineers have spent untold hours testing and evaluating the metallurgy of their distributor gears. The result is a perfect combination of metallurgical composition, heat-treating, and coatings to provide the most durable and accurate gear possible.

MSD's rotors are injection-molded from Rynite material for superior strength and dielectric properties. They also use deep, molded vanes to agitate the air inside the cap, preventing ionization. The stainless steel/brass tip is screwed in place, and the screws are set deep in the housing to prevent spark scatter.

Since we planned to leave the tissue dispenser on the shelf, we took this opportunity to remove its mounting brackets as well. Remember to torque the intake manifold bolts back to spec.

MSD supplies a new distributor gasket, so you'll want to remove all traces of the old one. Plug the hole with a rag to prevent gasket shrapnel from falling into the engine.

Now the fresh gasket can be put in place.

A packet of Comp Assembly Lube is also included with each distributor. Apply this liberally to the distributor gear before installation.

You can now set the distributor in place. Make sure the rotor is facing the same direction as the old one.

If it's not, use a screwdriver to turn the oil pump to achieve alignment. This may take a few tries to get right. You can then loosely bolt the hold-down bracket back in place.

Next, disconnect the wiring and remove the stock coil.

MSD's Blaster 2 coil is a direct replacement for the tired, old stocker. Simply bolt it in place.

Wiring is a piece of cake with MSD's included harness. It requires only three wires: red to coil positive, orange to coil negative, and black to ground.

With the terminal connections complete, plug the three-wire Weathertight connector to the distributor harness. Note the temporarily unused green wire. It supplies the needed signal to an electronic tachometer.

After consulting the directions for your ideal timing curve and rev limit, you can install the MSD distributor cap.

MSD also pitched in a set of 8.5mm Super Conductor plug wires. They are available in pre-terminated custom-length sets, or you can do as we did and make your own.

Beneath this plump plug boot is MSD's proprietary dual-crimp terminal. These are so secure that MSD warrants them against pulling apart for a full five years.

Lay out the wires as you wish. We chose to use the factory routing tabs on the valve covers, and it worked out nicely. The wires will need to be cut to the proper length before you install the terminals and boots.

Once the wires have been cut, you can strip the insulation using MSD's Pro-Crimp tool.

As the name implies, the Pro-Crimp also does a fine job at terminal crimping.

With the terminal properly crimped, you can slide the boot in place. A shot of silicone spray can make this easier.

Once you have the process mastered, it will only take you a few minutes to finish all eight plug wires and the coil wire. Install the wires as you complete them to keep from crossing them up.

You can reinstall the factory chrome shield if you wish, or go au naturel as shown here. Once you've got everything buttoned up, fire up the engine and set the initial timing. A dyno tune or a trip to the track is the best way to ensure you're extracting maximum performance from your new electronic ignition system.